The guitarrón is the backbone of mariachi music, anchoring the ensemble with musical bass lines and rhythmic pulse. It is a large stringed instrument, with a deep body and the lowest notes. Mariachi Tesoro de San Fernando’s guitarrón player has been described as “a beast,” “the heart of the mariachi,” and the one who “signals the whole song all the way through.”

Sitting in the audience of a panel featuring Mariachi Tesoro at the 2025 Smithsonian Folklife Festival, I heard a voice marvel behind me: “Oh, wow.”

Mariangel Esparza Lopez, clutching her guitarrón proudly on stage, surrounded by world-renowned mariachi masters, just graduated the eighth grade. “It’s always been amazing seeing all the opportunities I get to have,” she said. “Everybody [has been] telling me, ‘Congratulations for being so young and playing guitarrón!’”

This is not uncommon for Mariachi Tesoro, an ensemble famous for its musical excellence and empowerment of young musicians.

Emerging in the eighteenth century, mariachi is a blend of Indigenous, Spanish, other European, and African cultural influences. It is a folk-derived tradition that many consider the strongest musical representation of Mexican culture and identity.

(Watch Mariachi Tesoro in the Roots and Voices: Americana Reimagined concert on July 4)

Mariachi Tesoro traces its origins to Nati Cano, a Smithsonian Folkways artist and a legend within the mariachi community. Cano founded and led the award-winning Mariachi Los Camperos for several decades until his death in 2014. With inspiration and encouragement from arts advocate Virginia Diediker, Cano partnered Mariachi Los Camperos with the City of San Fernando, in Los Angeles County, creating the highly successful Mariachi Master Apprentice Program (MMAP). 

MMAP’s top branch, Mariachi Tesoro de San Fernando, showcases talented students of the program and pairs them with master musicians, with whom they learn and perform.

Natalia Diaz, a sixteen-year-old violinist with Mariachi Tesoro, is already preparing to lead the next generation of mariachi musicians.

“A lot of my friends and even myself have been inspired [by] this program to start our own groups and go play community events on our own time,” she shared with me over the phone. “I have my own little group with my friends”—all ages fourteen to sixteen. 

Mariachi Tesoro is led by Sergio Alonso, or Checo, a renowned musician, teacher, and ethnomusicologist.

“Students probably wouldn’t engage in school music if it wasn’t for [our] mariachi programs,” he shared. “When I have middle school students that come up and say, ‘I’m a violin player and I like mariachi music,’ I go, ‘well, you have a place here.’”

Nearly 80 percent of San Fernando’s population has Mexican heritage, making mariachi music familiar to many community members, including Mariangel. “Because I’m Mexican, it connects me back to my roots,” she said. “And because we are known, we go to places where people want to hear our music, and [we] meet so many wonderful people too.”

“Being a part of MMAP has really pushed me as a musician, especially with having to memorize music, because that’s a really key part of mariachi,” Natalia explained. MMAP’s curriculum embodies both oral tradition and music theory enrichment, so by the time students reach Mariachi Tesoro, they can play music after hearing it and sight read at high levels.

But the program has positive effects beyond musicianship. MMAP students have a graduation rate of 100 percent, 21 percent higher than the average in San Fernando’s public school district.

“I’ve become more outgoing,” Mariangel told me. “Being in front of a big crowd and doing that a lot helps you not to be as scared about doing it the next time… you’re already used to it.”

At the Smithsonian Folklife Festival, Tesoro demonstrated different mariachi styles, including boleros, polkas, sones arribeños, waltzes, and more. Visitors sang along passionately to popular songs like “Cielito Lindo” and sometimes shouted out requests, which the ensemble always seemed able to deliver.

One highlight for many Festival visitors was mariachi master Jesús “Chuy” Guzmán’s demonstration of a grito—a passionate shout to express joy and emotion in response to the music. The room filled with gritos as Tesoro’s musical set filled with increasing energy.

The young musicians revealed their versatility at the Festival when they collaborated with Sugar in the Pan! The Vermont-based band, which specializes in traditional music of New England and beyond, played a tune a couple of times through before Mariachi Tesoro musicians jumped in, filling the Music Room tent with joy and sound. The additions of trumpet, harp, guitarrón, and other mariachi instruments led visitors to sway with the music and hold up their phone to film it—myself included.

“I just love it,” Natalia said. “It’s an outlet to share my culture and learn more about it.”

Liv Berg is a program intern at the Smithsonian Folklife Festival and a graduate of UCLA with a bachelor’s degree in ethnomusicology.